{
  "id": "2023-09-20-mt-san-antonio-college-stabbing",
  "slug": "mt-san-antonio-college-stabbing-2023-09-20",
  "institution": {
    "name": "Mt. San Antonio College",
    "shortName": "Mt. SAC",
    "state": "CA",
    "type": "community-college",
    "alertSystemName": "Mt. SAC Alert",
    "alertPlatform": "Rave",
    "enrollment": 55000
  },
  "incident": {
    "date": "2023-09-20",
    "type": "stabbing",
    "cleryCategory": "emergency-notification",
    "headline": "One person stabbed during an altercation in a campus building; suspect arrested",
    "headlinePublic": "One person stabbed during an altercation in a campus building; suspect arrested",
    "summary": "On the morning of Wednesday, September 20, 2023, a [physical altercation in Building 26B](https://abc7.com/student-stabbing-mt-san-antonio-college-walnut-california/13806715/) at [Mt. San Antonio College](https://en.wikipedia.org/wiki/Mt._San_Antonio_College) escalated into a stabbing at approximately 11:30 AM PDT, with the victim suffering torso and neck wounds. The campus-wide [Mt. SAC Alert](https://sac.media/2023/11/20/is-mt-sac-safe/) was sent at roughly 12:10 PM PDT, about 40 minutes after the attack, a gap that drew criticism from students and faculty over the college's emergency notification practices throughout the fall. Suspect Gavin Flores, 18, was arrested on suspicion of attempted murder; classes in Buildings 26A, 26B, and 26D were canceled for the rest of the day.",
    "outcome": "Victim hospitalized with stab wounds to torso and neck; survived. Suspect Gavin Flores, 18, of West Covina, arrested on suspicion of attempted murder and held on $1 million bail; on October 1, charges were reduced: Flores ultimately pled no contest to a misdemeanor violation of Penal Code § 626.10 (weapons on school grounds) for one year of summary probation, 15 days of community labor, and search/seizure plus weapons conditions. Classes in Buildings 26A, 26B, and 26D canceled for the rest of Wednesday; campus reopened Thursday.",
    "resolution": "confirmed-threat",
    "casualties": {
      "killed": 0,
      "injured": 1
    }
  },
  "alerts": [
    {
      "sequence": 1,
      "type": "initial",
      "timestampApprox": "Wednesday, September 20, 2023, approximately 12:10 PM PDT, about 40 minutes after the 11:30 AM stabbing in Building 26B",
      "channel": "sms",
      "verbatimText": "MtSAC Alert: An altercation resulted in a physical attack at about 11:40 am. Police investigating. Suspect in custody. Witnesses please call (909) 274-4555.",
      "isVerbatimConfirmed": true,
      "sourceUrl": "https://sac.media/2023/11/20/is-mt-sac-safe/",
      "sourceDescription": "SAC Media (Mt. SAC student newspaper), which published the verbatim Mt. SAC Alert in its fall 2023 campus-safety investigation",
      "annotations": [
        "Reports the incident as occurring 'at about 11:40 am' (Mt. SAC's own timestamp); the LA County Sheriff's Department logged the 911 call at approximately 11:30 AM PDT, so the alert's stated time differs by about 10 minutes from the logged call time",
        "The alert went out approximately 40 minutes after the incident; Professor Shiloh Blacksher, who was on scene, raised the lag at the September 21 Academic Senate meeting along with concerns about construction obstructing EMS access and trauma-counselor response time",
        "The message uses present tense ('Police investigating', 'Suspect in custody') because by the time the alert went out, the suspect was already in custody; the alert was less a warning than a notification",
        "The alert did not instruct students in Building 26 to evacuate while the second-floor scene in 26B was still being processed",
        "Mt. SAC primarily uses Rave-based SMS and email; the same message was simultaneously posted to the college's main Facebook and X accounts"
      ],
      "characterCount": 156
    }
  ],
  "context": "[Mt. San Antonio College](https://en.wikipedia.org/wiki/Mt._San_Antonio_College) is the largest single-campus community college in California, serving roughly 55,000 students annually at its 421-acre campus in Walnut, eastern Los Angeles County. The September 20, 2023 stabbing began as an altercation over a female student between her current boyfriend and an ex-boyfriend, all three of whom were Mt. SAC students. According to LASD, the ex-boyfriend (Gavin Flores, 18, of West Covina) was the aggressor and pulled a knife, stabbing the female student's current boyfriend multiple times in the torso and neck on the second floor of Building 26B at 1100 N. Grand Avenue; the female student had previously reported Flores to Mt. SAC's Title IX office and police for harassment and stalking and was [in the process of filing a restraining order against him](https://sac.media/2023/11/20/is-mt-sac-safe/). The 18-year-old suspect, [Gavin Flores of West Covina, was taken into custody](https://abc7.com/student-stabbing-mt-san-antonio-college-walnut-california/13806715/) on suspicion of attempted murder and held on $1 million bail; charges were later reduced and he [pled no contest to a misdemeanor violation of Penal Code § 626.10](https://sac.media/2023/10/05/update-on-mt-sac-stabbing-incident/) for one year of summary probation. Much of the subsequent campus discussion focused on the Mt. SAC Alert response time. The campus-wide text alert went out roughly 40 minutes after the incident, did not instruct anyone in Building 26 to evacuate while the scene was still active, and timestamped the attack at '11:40 am', about 10 minutes later than the LASD-logged incident time. [Faculty and students raised the issue at the September 21 Academic Senate meeting](https://sac.media/2023/11/20/is-mt-sac-safe/), and the lag became the focal point of a fall-long campus-safety discussion that included [concerns from the Deaf and hard-of-hearing community about whether they could rely on the alert system](https://sac.media/2023/11/20/is-mt-sac-safe/), questions about construction obstructing EMS access, and complaints about trauma-counselor response time. By April 2024, [Mt. SAC committed to installing additional cameras](https://sac.media/2024/04/10/mt-sac-installing-cameras-amid-continuing-safety-concerns/) in response to the cluster of fall 2023 incidents, which also included two sexual assaults, a knife-point robbery, and a separate parking-lot attack. The case documents a notification that arrived after the actual threat had already been neutralized, the operational counterpart to false-positive cases such as swatting.",
  "keyFindings": [
    "Roughly 40 minutes elapsed between the stabbing and the campus-wide alert, which reported the suspect already in custody; faculty raised the lag at the September 21 Academic Senate meeting",
    "The alert's own timestamp ('at about 11:40 am') differs by about 10 minutes from the LA County Sheriff's logged incident time (approximately 11:30 AM PDT)",
    "The alert did not instruct students in Building 26 to evacuate; the crime scene was still being processed on the second floor while the building remained occupied",
    "The incident prompted a fall-long campus-safety discussion at Mt. SAC, including concerns from ACCESS and the Deaf/hard-of-hearing community about whether SMS-only alerts adequately served them"
  ],
  "sources": [
    {
      "title": "Altercation between three people leads to stabbing at Mt. SAC - SAC Media",
      "url": "https://sac.media/2023/09/20/altercation-between-three-people-leads-to-stabbing-at-mt-sac/",
      "type": "student-newspaper"
    },
    {
      "title": "Is Mt. SAC safe? - SAC Media (fall 2023 campus-safety investigation)",
      "url": "https://sac.media/2023/11/20/is-mt-sac-safe/",
      "type": "student-newspaper"
    },
    {
      "title": "Update on Mt. SAC stabbing incident - SAC Media",
      "url": "https://sac.media/2023/10/05/update-on-mt-sac-stabbing-incident/",
      "type": "student-newspaper"
    },
    {
      "title": "Student stabbed at Mt. San Antonio College in Walnut; suspect arrested - ABC7 Los Angeles",
      "url": "https://abc7.com/student-stabbing-mt-san-antonio-college-walnut-california/13806715/",
      "type": "local-media"
    },
    {
      "title": "Altercation over female student leads to stabbing at Mt. San Antonio College - KTLA",
      "url": "https://ktla.com/news/local-news/1-in-custody-after-stabbing-at-mt-san-antonio-college/",
      "type": "local-media"
    },
    {
      "title": "Mt. SAC installing cameras amid continuing safety concerns - SAC Media",
      "url": "https://sac.media/2024/04/10/mt-sac-installing-cameras-amid-continuing-safety-concerns/",
      "type": "student-newspaper"
    }
  ],
  "confidence": "medium",
  "tags": [
    "community-college",
    "stabbing",
    "mt-sac",
    "california",
    "response-time-lag",
    "clery-act",
    "attempted-murder",
    "walnut",
    "accessibility-concerns",
    "delayed-alert"
  ],
  "dateAdded": "2026-05-13",
  "lastUpdated": "2026-07-16",
  "addedBy": "ingestion"
}